5 young Cardinals who have answered the call so far and 3 who haven't

Matthew Liberatore's transition to the rotation has proven that he can be a top-of-the-rotation starting pitcher.

I wrote last week about Matthew Liberatore's path to the starting rotation. After being jockeyed around as a reliever and a starter in both the majors and minors, Liberatore was finally given a consistent role out of a solid spring training. Give that piece a read here.

For years, Liberatore's development has been sacrificed by other needs on the roster. The club has tried using him as a bulk reliever, a high-leverage lefty, and a fireman of sorts. He was also given chances to start in the past, but he wasn't built up or prepared like a normal starter would be. Now that he's been given ample time to prepare, Liberatore is taking full advantage of this opportunity during the youth movement.

Matthew Liberatore has been one of baseball's best left-handed starting pitchers to start the year. Among qualified left-handed starters, Libby ranks fourth in fWAR (1.5), thirteenth in ERA (3.11), third in walk rate (3.8%), and fourteenth in ERA- (77, where 100 is average and lower is better).

Libby has found success this year by using his changeup more against right-handed batters. Righties are hitting just .105 against his changeup this year. Liberatore's altered changeup, paired with his plus fastball and slider, has made him a dominant starter against all batters regardless of handedness.

Liberatore has made a nice pairing with Sonny Gray at the top of the Cardinals' rotation, and he's made the most of his chance to be a regular starter so far. He stands to be one of the team's best starters and one of the league's best left-handed starters for the Cardinals' next window of competition following the retool this year.